1. Field
One or more embodiments relate to a motion sensing apparatus and method.
2. Description of the Related Art
Input information may be directly input, through a keypad, and the like, to a portable terminal or a hand-held type device. However, recently, information for such devices has been input through the sensing of motion information of a user using various sensors, and by analyzing the sensed motion information to sense an input signal of a corresponding device.
The inputting of the input signal based on the motion of the user is more intuitive compared with more traditional input/output (I/O) methods such through utilizing a button, a keyboard, and the like, and is capable of successively inputting the input signal, thereby providing a high utilization. Also, the inputting of the input signal based on the motion of the user may include calculating a rotational angle to estimate corresponding motion information.
An Attitude and Heading Reference system (AHRS) is widely used as a motion sensing apparatus, with the AHRS estimating a rotational angle by utilizing a 3-axis accelerometer sensor, a 3-axis angular velocity sensor, and a 3-axis geomagnetic sensor, for example.
A system that performs a 2-dimensional (2D) motion and receives heading information by a GPS receiver, may use an Attitude Reference system (ARS) that estimates the rotational angle using the 3-axis accelerometer sensor and the 3-axis angular velocity sensor, excluding the geomagnetic sensor from the AHRS, for example.
Still further, a method of estimating the motion information only using the 3-axis accelerometer sensor and the 3-axis angular velocity sensor may only calculate a relative rotational angle instead of an absolute rotational angle of an axis, which may result in errors due to drift, for example, and thus the method may be widely used for estimating a rotational angle of another axis in addition to the corresponding axis.